BIOLOGY 2EE3 Lecture Notes - Lecture 1: Rna World, Decomposer, Heterotroph
23 Jun 2018
School
Department
Course
Professor
Introduction to Microbial World
Three organismal domains
The linear distance is proportional to sequence similarity of the SSU
rRNA gene sequences from organisms corresponding to the
endpoints
Vitamin B12 (Cobalamin)
The only organisms that produce it are bacteria and archaea
Important because it contains biochemically rare element Cobalt
Important for the formation of blood and the proper function of the brain and the nervous system.
Human B-12-dependent enzymes are methylmalonic and homocysteine
Lack of B-12 causes the buildup of substrates of the enzymes that are dependent on B-12.
Louis Pasteur
Disproved the theory of spontaneous generation
He placed sterile nutrient broth in a swan-necked flask. The bacteria from the air would get stuck in the neck
and not be able to enter. Thus, broth remains sterile. But if he tilted the flask and allowed it to come in
contact with the bacteria from air, then microbes were seen.
Pasteurization requires
63 C for 30 minutes
72 C for 15 seconds
Koch’s Postulates
1) Organism must be present in all cases of the disease
2) Isolate organism and grow in pure culture
3) Pure culture must cause same disease when inoculated into susceptible host
4) Same organism must be isolated from the inoculated disease host (animal)
The Black Death: Plaque
Killed 1/3 of Europe’s population
Caused by Yersinia pestis
It infects rodents, thus it grows in the rat’s bloodstream. The fleas’ feed on the rodent - thus bacteria now
infect its gusts. The fleas then bite on humans as an alternative host causing disease and death in humans.
Reduction in death from infectious disease
Public sanitization (eg. sewage system)
Personal hygiene improvements
Water/Food safety (pasteurization)
Vaccines (introduce human to a weakened version of a microbe to create immunity in body)
Antiseptics
Treatment of bacteria (antibiotics)
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Document Summary
The linear distance is proportional to sequence similarity of the ssu rrna gene sequences from organisms corresponding to the endpoints. The only organisms that produce it are bacteria and archaea. Important because it contains biochemically rare element cobalt. Important for the formation of blood and the proper function of the brain and the nervous system. Human b-12-dependent enzymes are methylmalonic and homocysteine. Lack of b-12 causes the buildup of substrates of the enzymes that are dependent on b-12. He placed sterile nutrient broth in a swan-necked flask. The bacteria from the air would get stuck in the neck and not be able to enter. But if he tilted the flask and allowed it to come in contact with the bacteria from air, then microbes were seen. Koch"s postulates: organism must be present in all cases of the disease. Pure culture must cause same disease when inoculated into susceptible host. Same organism must be isolated from the inoculated disease host (animal)
